Trench digger



Dec., 20, 1949 T. K. ANDERSEN 2,491,793

TRENcH umm-:R

Filed Nov. 6, 1945 3 Sheets-Sheet 1 Dec.. 20,', 1949 T. K. ANDERsEN TRENCH BIGGER 3 Sheets-Sheet 2 Filed Nov. 6, 1945 INVENTOR. Thawras /f Hna/:sew

ATTORNET.

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Dee. 20, 1949 T. K. ANDERsEN TREHCH BIGGER Filed Nov. e, 1945 end is a pyramidal hood 22 having thereon, at its upper end 23, a pivot shaft 24, and a cable anchor 25. Secured tc the cable anchor 25 is the rear end of a lifting cable 26 for raising and lowering the boom I3 and bucket I5. The forward end of the cable 26 is made fast to any suitable winch, or equivalent mechanism, shown diagrammatically at 26'. Where a winch is employed, lt is preferably driven from the tractor motor (not shown) under the control of the operator thereof, through a suitable clutch and clutch lever (not shown). By this construction the boom i8 may be lowered to move the bucket i to digging position, and upwardly preparatory to being dumped.

The rotary movement of the bucket l5 to bring the same into digging position and filling the same, and for dumping the content thereof when filled is controlled by the mechanism now to be described.

Pivotally mounted on shaft 2li is the rear end of a link 21, the forward end of which is pivoted on a shaft 23 secured to the upper end of a vertically disposed pair of links 29 arranged on the sides of and preferably near the middle of i the boom i3. The lower ends of links 2t are secured to the ends of a pivot shaft 39B, rotatably mounted in the boom i3.

Also pivotally mounted on pivot shaft 2d is the rear end of a link section 3i. This link section is bifurcated at its forward end, and in a slot formed in this end is secured a latch member 32 in which is formed a latch socket (see Fig. 5) while at the rear end is a bevel face 3&1. The bifurcated end of link section Si is slidably mounted in the open rear end of a link section 35, and the upper face of such link section 35 is slotted, as at 35, to permit passage of the latch member 32. Within link section at its extreme forward end, is housed a coiled buffer spring 31, against which may abut the forward end of the link section 3i.

Link section 35, at its forward end, is provided with a forked member 33, and is pivotally mounted on a shaft 39, which may be inserted in any one of a plurality of holes rita, 40o, 4c and 40d formed in a vertical plate fil mounted on or forming part of the support i i. The holes 40a, 4th, 411e and ltd are used in conjunction with the link sections 35, 3i and 21 to control the tilt of bucket I5, as will be more fully explained hereinafter.

Welded to the rear end of link section 35, on either side of slot 36, and separated by a spacer 42', are plates 42. A bolt 43, passing through plates 42A and spacer 42 holds the link section against distortion. Aligned bearings are formed in plates 42, and in such bearings is rotatably mounted a shaft 44. This shaft extends outwardly through the plates 42 and has secured thereto a pair of latch plates 45. The latch plates 45 are substantially wedge shaped, with the apex ends thereof extending downwardly to a point below link section 35 for contact with the upper surface of boom i3. The upper ends of plates 45 are secured together in any suitable manner, as by a transverse bar 4t.

At the forward ends of latch plates 45 is arranged a series of aligned holes 41, these being arcuately arranged. In these aligned holes is removably mounted a shaft 48, on which, and between the latch plates 45, is rotatably mounted a latch roller 49, which cooperates with latch socket 33 to hold link sections 3l and 35 in the relation shown in Fig. 5. By varying the position of shaft 48 in the series of holes 41, the

projection of the latch plates 45 below link Il may be varied.

Springs B0, secured at one end to the latch plates 45, and at their other end to link section 35, tend to hold the roller 49,111 the socket 33 in the locked position shown in Fig. 5, and to return such members to the position shown after the link sections 3l and 35 have been telescoped and are again returned to their original position.

The operation of the apparatus is as follows:

In Figure 3, the apparatus is shown in full lines in the digging position to which it has been lowered by the operator in control of cable 23. When thus positioned the operator moves the tractor forward, digging the teeth I9 into the earth 5I, thus filling the bucket I5.

When the bucket I5 is filled, the operator, by means of the cable 26,- lifts the bucket I5 upwardly clear of the trench being dug, as shown in the dot or dash line figure immediately above the full line position shown in Figure 3. It will be noted that no rotary movement of the bucket i5 has taken place, and therefore the bottom I1 of the bucket i5 lies practically horizontal, thus retaining the load in the bucket.

The operator will now, by swinging the tractor, swing the boom i3 laterally until the bucket I5 is over the position where it is desired to deposit the load. As the bucket is lifted, the downwardly projecting latch plates 45 contact the top part of the boom i3, which may carry a wear plate 52 at this point. Such contact lifts latch plates 45 and roller 49 and permits link 3l to telescope into link 35 until its forward end contacts buffer spring 39. The telescoping of the links 3l and 35 permits the bucket I5 to rotate about its pivotal mounting I4, such rotation being caused by the weight of the material in the bucket and the pull of the cable 26. bucket is shown in the topmost dash or dot line position in Fig. 3. It will be noted that the bucket I5 is now in dumping position, and the load therein has been deposited at the required spot. The dumping operation is facilitated by the rotary movement of the bucket I5 about the fixed scrapers 20 and 2I.

In order to return the empty bucket tc its original position, the operator first releases the cable 26 which permits the bucket to drop until teeth I9 contact the ground.

The operator then backs up the tractor a short distance. rearwardly away from link section 35 and roller 4B to be lifted by cam surface 34 into position to be again returned into socket 33 by the action of springs 50.

If the bifurcated end of link section 35 is connected to plate II at hole 40h and the bottom I1 of the bucket is in the same plane as the ground, then as bucket I 5 is lifted the bottom I1 will stay in the same plane as the ground throughout its cycle.

If digging conditions are such that the bottom I1 being in the same plane as the ground will not permit the bucket to dig, then the bifurcated end of link section 35 may be connected in hole 40d. 'I'his will Iincline the front edge of bucket bottom I1 downwardly with relation to the ground which gives it greater digging ability. When in hole 40d, the relation of the bucket bottom I1 to the ground is also maintained throughout its lifting cycle.

1f the bifurcated end of link section as is connected to hole 40e, the front edge of bucket bottom I 1 will be somewhat downwardly inclined This position of the This causes link section 3| to be pulled i 5 with relation to the ground but as the bucket is lifted throughout its cycle this relationship will change until at the top of the cycle the front edge of the bucket bottom will be upwardly inclined with relation to the ground. This action would be of considerable advantage in digging and handling materials, such as sand or loose gravel, which ilow easily.

If the bifurcated end of link section I5 is connected to hole Ila, the reverse of the action just described will take place.

Although I have shown my digging apparatus applied to a tractor, it obviously may be used with vehicles other than tractors. The design of the bucket or other digging implement will likewise depend upon the nature of the work to be performed. Where trenches are to be dug, such implement will take the form of a digging bucket, such as is shown in the present application. Where other excavating work is to be performed, the digging implement will be appropriately designed to best perform such work.

Various other modifications in construction and design may obviously be resorted to without departing from the spirit and scope of my invention as denned by the appended claims.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent is:

1. A digging apparatus for attachment to a vehicle, comprising a boom pivotally mounted at one end upon one end of the vehicle, a digging implement pivotally mounted upon the outer end of the boom, a collapsible linkage having one end pivotally attached to said digging implement and the other end pivotally attached to one end of said vehicle, means forming part of the linkage lor holding it in selected extended position, means for swinging the boom in a vertical plane about its connection to the vehicle, and means con- '0 nected to said holding means and actuated by said boom for releasing said holding means and to collapse and shorten said linkage when said boom is positioned at a predetermined vertical angle with respect to said vehicle.

2. A digging apparatus as set forth in claim 1, in which the linkage comprises two pivotally attached arms, the pivot connection of the two arms being pivotally connected to the boom. by a connecting linkage.

3. A digging apparatus as set forth in claim l, and in which a load releasing member is assocated with the digging implement, and a lmmovably attached to the rear end of the boom, whereby the load in the digging implement is loosened upon swinging movement of the digging implement about its pivotal mounting during the dumping operation. M

4. A digging apparatus as set forth in claim 1, and in which the linkage is formed of two pivotally attached link members, one of said members comprising two sections telescoped together, and with the means forming part of the linkage for selectively holding it in extended position constituting a releasable locking device for maintaining the members in extended position, a releasing means forming part of said locking device, and means carried by the boom to operate the releasing means of the locking device to permit telescoping of the members to thereby shorten the linkage.

THOMAS K. ANDERSEN.

REFERENCES CITED The yfollowing references are of record in the ille of this patent:

UNITED STATES PA'I'ENTS 2,398,585 Hayward Apr. 16, 11946 

